Method for producing an organic el display device

ABSTRACT

A method includes: forming, in a first substrate, a display area in which a plurality of pixels including an organic EL light-emitting layer are arrayed; forming, in a second substrate, a plurality of opening areas respectively located in correspondence with the plurality of pixels and a light-blocking area that demarcates the plurality of opening areas; providing a dam material such that the dam material encloses the display area; dripping a filler material to an area enclosed by the dam material; and attaching the first substrate and the second substrate to each other, and fusing together dripped portions of the filler material, thereby bonding the both substrates to each other. The both substrates are attached to each other while being positionally aligned such that borders between the dripped portions of the filler material that is generated by the fusion are located in an area corresponding to the light-blocking area.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.14/574,762, filed on Dec. 18, 2014, issued as U.S. Pat. No. 9,356,254.Further, this application is based upon and claims the benefit ofpriority from the prior Japanese Patent Application No. 2013-266086,filed on 24 Dec. 2013, the entire contents of which are incorporatedherein by reference.

FIELD

The present invention relates to an organic EL (electro-luminescence)display device including a sealing unit for an organic EL light-emittinglayer, and a method for producing the same.

BACKGROUND

Recently, organic EL display devices have been progressively developedfor decreasing the thickness, raising the luminance and increasing theoperation speed of display panels. An organic EL display device is adisplay device including pixels formed of organic light-emitting diodes.The organic EL display device has high response speed because nomechanical operation is needed, is capable of providing high luminancedisplay because each pixel itself emits light, and can have reducedthickness because a backlight unit is not needed. For these reasons, theorganic EL display device is favorably expected to be a next-generationdisplay device.

In such an organic EL display device, an organic EL light-emitting layeris rapidly deteriorated when being exposed to moisture and thus needs tobe shielded against external air. Therefore, some conventional organicEL display devices have a structure in which a surface of the organic ELlight-emitting layer is covered with a sealing film and bonded to acounter substrate, including color filters or the like, with atransparent resin being sandwiched between the organic EL light-emittinglayer and the counter substrate (see, for example, Patent Literature 1,“Japanese Laid-Open Patent Publication No. 2001-338754”).

A conventionally known method for producing an organic EL display devicehaving such a structure is as follows. As shown in FIG. 9, resins 4 and5 are dripped onto a substrate 7, including an organic EL light-emittinglayer, to form dot portions, and a counter substrate 6 is attached tothe substrate 7 while the resins 4 and 5 are sandwiched between thesubstrates. The resins 4 and 5 are pushed and expanded, and are cured tobond the two substrates.

However, the above-described conventional method for producing theorganic EL display device has the following problem. As shown in FIG.10, the resin 5 is dripped to form a plurality of dot portions 5 a, andthe dot portions 5 a are pushed and expanded by the step of attachingthe substrate 7 and the counter substrate 6 to each other. As a result,the dot portions 5 a adjacent to each other are fused together, andborders along which the dot portions 5 a are fused together may appearas striped display irregularities 55 z. As shown in FIG. 10, suchdisplay irregularities 55 z are visually recognized as lattice-likedisplay irregularities 55 z, which may deteriorate the image quality ofthe organic EL display device.

In Patent Literature 1, the display irregularities 55 z as shown in FIG.10 are considered to be caused by stress that is generated when theresin 5 is cured and contracted. Thus, the organic EL display devicedescribed in Patent Literature 1 includes an organic film between thesubstrates 6 and 7 in order to alleviate the stress, in addition to theresin sealing film. However, such a structure enlarges the gap betweenthe substrate 7 and the counter substrate 6. When the organic EL displaydevice is observed in an oblique direction, light emitted by the organicEL light-emitting layer is not transmitted through a corresponding colorfilter but is transmitted through an adjacent color filter. This maycause color mixing in the pixels. In addition, the structure in which aplurality of layers are provided between the substrates 6 and 7obstructs thickness reduction of the organic EL display device and sizereduction of the pixels, and also may complicate the production stepsand raise the production cost.

SUMMARY

A method for producing an organic EL display device in an embodimentaccording to the present invention includes: forming, as a component ofa first substrate, a display area in which a plurality of pixelsincluding an organic EL light-emitting layer are arrayed; forming, ascomponents of a second substrate, a plurality of opening areasrespectively located in correspondence with the plurality of pixels anda light-blocking area that demarcates the plurality of opening areas;forming a sealing film so as to cover the organic EL light-emittinglayer in the first substrate; providing a dam material on the sealingfilm such that the dam material encloses the display area; dripping afiller material to an area enclosed by the dam material by use of a jetdispenser or an inkjet device; and attaching the first substrate and thesecond substrate to each other while the dam material and the fillermaterial are sandwiched between the first substrate and the secondsubstrate, and fusing together dripped portions of the filler materialthat are adjacent to each other, thereby bonding the first substrate andthe second substrate to each other. The first substrate and the secondsubstrate are attached to each other while being positionally alignedsuch that borders between the dripped portions of the filler materialthat is generated by the fusion is located in an area corresponding tothe light-blocking area.

The opening areas may each include a color filter; and thelight-blocking area may include a black mask.

The filler material may be dripped at a dripping pitch that is shorterthan or equal to 100 λm.

An organic EL display device in an embodiment according to the presentinvention includes: a first substrate including a display area in whicha plurality of pixels including an organic EL light-emitting layer arearrayed; a second substrate that faces the first substrate and includesa plurality of opening areas respectively located in correspondence withthe plurality of pixels and a light-blocking area that demarcates theopening areas; a dam material provided between the first substrate andthe second substrate so as to enclose the display area; and a fillermaterial filling a space enclosed by the first substrate, the secondsubstrate and the dam material. The filler material includes bordersgenerated as a result of a plurality of portions of the filler materialbeing fused together; and the borders of the filler material are locatedin an area corresponding to the light-blocking area.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a cross-sectional view schematically showing a stack structureof an organic EL display device in an embodiment according to thepresent invention;

FIG. 2 is a planar see-through view showing a schematic structure of theorganic EL display device in an embodiment according to the presentinvention;

FIG. 3 shows a production step of the organic EL display device in anembodiment according to the present invention;

FIG. 4 shows production steps of the organic EL display device in anembodiment according to the present invention;

FIG. 5 shows production steps of the organic EL display device in anembodiment according to the present invention;

FIG. 6 shows production steps of the organic EL display device in anembodiment according to the present invention;

FIG. 7 shows production steps of an organic EL display device in example1 according to the present invention;

FIG. 8 shows production steps of an organic EL display device in example2 according to the present invention;

FIG. 9 shows production steps of a Conventional organic EL displaydevice; and

FIG. 10 shows a conventional organic EL display device.

DESCRIPTION OF EMBODIMENTS

The present invention is to solve the problems of a conventionalstructure and has an object of providing an organic EL display devicehaving improved image quality and realizing high definition display. Thepresent invention also has an object of providing a method for producingsuch an organic EL display device at low cost.

Hereinafter, an embodiment of the present invention will be describedwith reference to the drawings. The present invention is not limited tothe following embodiment and may be carried out in any of various formswithout departing from the gist thereof.

FIG. 1 is a vertical cross-sectional view showing an example of stackstructure of an organic EL display device 10 in an embodiment accordingto the present invention. As shown in FIG. 1, an organic ELlight-emitting layer 1 is formed on a transparent substrate 2 formed ofglass or the like. Although not shown in detail in FIG. 1, the organicEL light-emitting layer 1 may include, for example, a TFT drivingcircuit layer, a reflection electrode, a hole injection layer, a holetransport layer, a light-emitting layer, an electron transport layer, anelectron injection layer, and a transparent electrode that are stackedin this order from the side of the substrate 2.

The organic EL light-emitting layer 1 is rapidly deteriorated when beingexposed to moisture, and thus needs to be shielded against external air.Therefore, a surface of the organic EL light-emitting layer 1 is coveredwith, for example, a transparent sealing film 3 including a SiN filmformed by CVD. Hereinafter, a substrate 7 including the organic ELlight-emitting layer 1 and the sealing film 3 will be referred to as a“first substrate”. In FIG. 1, the first substrate 1 includes thesubstrate 2, and the organic EL light-emitting layer 1 and the sealingfilm 3 that are provided on the substrate 2.

The first substrate 7 including the organic EL light-emitting layer 1and the sealing film 3 is further covered with a sealing substrate(hereinafter, referred to as a “second substrate”) 6 so that the organiclayer is shielded against external air. Although not shown in detail inFIG. 1, the second substrate 6 may include a color filter, a thin filmdevice having a touch-panel function (e.g., touch sensor) or the likeformed on a transparent member formed of glass or the like.

A gap between the first substrate 7 and the second substrate 6 is filledwith transparent resins 4 and 5 such as epoxy resins or the like(ultraviolet-curable resin, thermosetting resin, etc.). Owing to this,the second substrate 6 and the first substrate 7 can be bonded to eachother while being distanced from each other by a certain length. Thiscan keep a surface of the first substrate 7 and a surface of the secondsubstrate 6 parallel to each other and prevent reflection and refractionat an interface between the surfaces.

FIG. 2 shows a schematic structure of the organic EL display device 10in an embodiment according to the present invention. Specifically, FIG.2 is a planar see-through view of the organic EL display device 10showing a shape of the surface of the first substrate 7 and also showingthe second substrate 6 seen through the first substrate 7.

As shown in FIG. 2, the organic EL display device 10 in an embodimentaccording to the present invention includes a display area 101 in whicha plurality of pixels including an organic EL light-emitting layer arearrayed, a frame area 102 that is an area outer to the display area 101,and a terminal area 103 in which terminals that electrically connect theorganic EL display device 10 to an external element are located.

On the first substrate 7, the resin 4 having relatively high pre-curingviscosity is located in the frame area 102. A space enclosed by theresin 4 is filled with the resin 5 having relatively low pre-curingviscosity. Since the resin 4 having relatively high pre-curing viscosityencloses the resin 5 having relatively low pre-curing viscosity, theresin 5 having relatively low viscosity can be prevented from flowingoutside even before being cured, while being expanded over the surfaceof the first substrate 7 uniformly. Hereinafter, because of such afunction difference between the resins 4 and 5, the resin 4 havingrelatively high pre-curing viscosity will be referred to as a “dammaterial”, and the resin 5 having relatively low pre-curing viscositywill be referred to as a “filler material”.

Now, with reference to FIG. 3, a step of attaching the first substrate 7and the second substrate 6 by use of the dam material 4 and the fillermaterial 5 will be described. FIG. 3 shows a production step of theorganic EL display device 10 in an embodiment according to the presentinvention. Specifically, FIG. 3 shows a production substrate 200, whichincludes a plurality of the first substrates 7 formed integrally. FIG. 3also shows positions on the production substrate 200, at which the dammaterial 4, the filler material 5 and a peripheral seal 9 are applied.

Generally for producing organic EL display devices, a plurality ofdevice patterns are formed on one glass substrate in consideration ofproductivity. In a similar manner, one production substrate includes aplurality of the second substrates 6 formed integrally. Hereinafter, theproduction substrate 200 shown in FIG. 3 will be described as asubstrate including the first substrates 7. Alternatively, theproduction substrate 200 may include the second substrates 6. Theproduction substrate including the first substrates 7 formed integrally,and the production substrate including the second substrates 6 formedintegrally, are bonded together, and then the resultant assembly is cutinto a plurality of individual organic EL display devices 10.

The step of attaching the substrates is performed in a chamber that actsas a production device (not shown). In the production device (notshown), the dam material 4 is first applied to the production substrate200 including the plurality of first substrates 7 formed integrally, byuse of a device that ejects a certain amount of liquid, for example, adispenser or the like.

The dam material 4 is applied to the frame areas 102, namely, alongperimeters of rectangles, so as to enclose the display areas 101. Inthis embodiment, an ultraviolet-curable epoxy resin, for example, isused as the dam material 4. Although not shown in FIG. 3, a spacermaterial that keeps a certain distance between the first substrates 7and the second substrates 6 may be optionally applied to the productionsubstrate 200. As shown in FIG. 3, the peripheral seal 9 is applied toan area in the vicinity of an outer perimeter of the productionsubstrate 200 including the plurality of first substrates 7 formedintegrally. As the peripheral seal 9, the same material as that of thedam material 4 may be used.

Next, the filler material 5 is dripped onto the areas enclosed by thedam material 4 by use of a jet dispenser, an inkjet device or the like.In this embodiment, a thermosetting epoxy resin, for example, is used asthe filler material 5. As shown in FIG. 3, the filler material 5 isdripped onto the areas enclosed by the dam material 4 to form dotportions. A reason why the filler material 5 forms dot portions is thatthe dripped filler material 5 assumes a spherical form because of thesurface tension thereof. The filler material 5 is dripped such that thedot portions of the filler material 5 are distanced from each other by acertain regular interval and thus form a matrix.

In this embodiment, the filler material 5 is dripped by use of a jetdispenser or an inkjet device, so that the amount of the filler material5 dripped each time can be smaller as compared with when a usual screwtype dispenser or pressurized dispenser is used. The dripping pitch(distance between positions to which the filler material 5 is dripped)is decreased by such a method. Thus, even when the total amount of thefiller material 5 is small under certain conditions, an appropriateamount of the filler material 5 can be dripped at appropriate positionsover the entire areas enclosed by the dam material 4 with no fillingdefect. This can be rephrased as follows. The gap between the firstsubstrate 7 and the second substrate 6 that are attached to each otherdepends on the total amount of the filler material 5 dripped; and evenwhen the total amount of the filler material 5 is small, the fillermaterial 5 can be expanded uniformly over the entire area enclosed bythe dam material 4. Therefore, the first substrate 7 and the secondsubstrate 6 can be bonded together while the gap therebetween is kept tocertain narrowness. As can be seen, according to the production methodin this embodiment, an organic EL display device having a narrow gapbetween the first substrate 7 and the second substrate 6 can beproduced. Such an organic EL display device can prevent color mixing inthe pixels and can also be thin.

The dripped filler material 5 is pushed and expanded by the step ofattaching the substrates described later, and thus the adjacent dotportions of the filler material 5 are fused together. With theconventional technology, borders along which the dot portions of thefiller material 5 are fused together often cause a fusing defect. Thiswill be described specifically. When being pushed and expanded, thefiller material 5 may undesirably incorporate, for example, acuring-inhibiting substance (substance that inhibits curing of theresin) that is present on the substrate but is not intended to beincorporated. As a result, the state of the filling material 5 at theborders is inferior to the state of the filling material 5 in theremaining area. In addition, since the state of the filler material 5 atthe borders is different from the state of the filling material 5 in theremaining area, the filler material 5 at the borders may not besufficiently cured when, for example, being irradiated with ultravioletor heat-treated as described later. When such an area that is notsufficiently cured is heated by, for example, a reliability test or thelike after the production of the organic EL display device 10 isfinished, the filler material 5 at the borders is progressively curedand contracted. This applies a stress to the second substrate 6, and asa result, the display irregularities 55 z as shown in FIG. 10 may becaused.

In this embodiment, in order to alleviate such a cause of the displayirregularities 55 z, a jet dispenser or an inkjet device as describedabove is used so that the dripping pitch of the filler material 5 isdecreased. The dot portions of the dripped filler material 5 are fusedwithin a short time, and thus the state of the filler material 5 at theborders can be better. In addition, the distance by which the dotportions of the filler material 5 are expanded by the time when the dotportions are fused together is shortened. Therefore, the amount ofcuring-inhibiting substance that may be incorporated into the fillermaterial 5 on the substrate can be decreased. In the case where thedripping pitch of the filler material 5 that is dripped by use of a jetdispenser or an inkjet device is, for example, shorter than or equal to100 μm, the display irregularities 55 z are not visually recognized.

Therefore, the method for producing the organic EL display device 10 inan embodiment according to the present invention can alleviate thedisplay irregularities 55 z that may be visually recognized. Inaddition, the production steps can be simplified and the production costcan be reduced by use of an existing jet dispenser or inkjet device. Asdescribed above, the gap between the substrates 6 and 7 can be decreasedto prevent color mixing in the pixels. Therefore, the resultant organicEL display device 10 can be thin and realize high definition display.

As described above, the filler material 5 is dripped onto the productionsubstrate 200 by use of a jet dispenser or an inkjet device. After this,the production substrate 200 including the plurality of first substrates7 formed integrally, and the production substrate including theplurality of second substrates 8 formed integrally, are located to faceeach other and attached to each other. The inner pressure of the chamberthat accommodates the two production substrates is decreased, and thetwo substrates are positionally aligned to each other by use of,optionally, alignment marks formed on both of the substrates while thegap between the substrates is narrowed. As a result, the dam material 4applied to the production substrate 200 is put into contact with theother production substrate, and spaces enclosed by the dam material 4and the two substrates are formed. Then, the inner pressure of thechamber is made the atmospheric pressure, so that the two substrates canbe pushed against each other at the atmospheric pressure. As a result,the filler material 5 expands in the spaces enclosed by the dam material4 and the two substrates, and the areas defined by the dam material 4are filled with the filler material 5. In order to prevent generation ofair bubbles or vacuum reservoir, this step of attachment is completedbefore the viscosity of the dam material 4 and the viscosity of thefiller material 5 are raised.

In this step, owing to the peripheral seal 9 on the production substrate200, the areas enclosed by the peripheral seal 9 and the two substratescan be kept in a low-pressure state even after the atmospheric pressureis introduced. Therefore, the atmospheric pressure is directly appliedto the dam material 4 around the display areas 101, which can preventthe dam material 4 from being invaded by the air and thus from beingdestroyed.

Next, the dam material 4 and the filler material 5 are cured. The dammaterial 4 is irradiated with ultraviolet to be cured, and then theattached substrates are put into a heat treatment furnace. In the heattreatment furnace, the filler material 5 and the dam material 4 arethermally cured.

By the above-described steps, the bonding of the substrates by use ofthe dam material 4 and the filler material 5 is completed. After thesubstrates are bonded together, the production substrates are cut by useof a known method such as a scribe-and-break method or the like to beseparated into individual pieces. A part of each second substrate 6 thatfaces the terminal area 103 of the first substrate 7 is cut away andremoved, and an external circuit such as a driver IC or the like isconnected to each terminal area 103. Thus, individual organic EL displaydevices 10 as finished products are produced.

Now, with reference to FIG. 4 through FIG. 6, a part of the step ofattaching the substrates in the method for producing the organic ELdisplay device 10 in an embodiment according to the present inventionwill be described. Specifically, adjustment of dripping positions towhich the filler material 5 is to be dripped will be described in moredetail. FIG. 4 through FIG. 6 show steps for producing the organic ELdisplay device 10 in an embodiment according to the present invention.FIG. 4 through FIG. 6 show the step of attaching the first substrate 7and the second substrate 6 for the sake of description. In actuality,however, the production substrate 200 and the like described above areattached together.

FIG. 4(a) is a planar see-through view of the organic EL display device10 showing, with dashed lines, opening areas 20 a through which lightfrom the organic EL light-emitting layer 1 is transmitted. FIG. 4(b) isa cross-sectional view taken along line A-A′ in FIG. 4(a). FIGS. 5(a)and 5(b) are each a planar see-through view of the organic EL displaydevice 10 showing a process in which the filler material 5 dripped ontoa center part of each of the opening areas 20 a is pushed and expanded.FIG. 5(c) is a cross-sectional view taken along line B-B′ in FIG. 5(b).FIG. 6(a) is a planar see-through view of the organic EL display device10 showing a state where adjacent dot portions of the filler member 5are fused together. FIG. 6(b) is a cross-sectional view taken along lineC-C′ in FIG. 6(a).

In FIG. 4(a), the opening areas 20 a, which are respectively located incorrespondence with the pixels or sub pixels and through which lightfrom the organic EL light-emitting element 1 is transmitted, arerepresented with dashed quadrangles. An area that demarcates the openingareas 20 a is shown as a light-blocking area including a black mask 22.As shown in FIG. 4(b), a color filter 21 is provided in each openingarea 20 a. In the light-blocking area, the black mask 22, lines of adriving element and the like are provided. As shown in FIG. 4(b), thecolor filter 21 and the black mask 22 are formed in the second substrate6. The gap between the first substrate 7 and the second substrate 6 isfilled with the filler material 5, and thus the first substrate 7 andthe second substrate 6 are bonded together.

With reference to FIG. 5 and FIG. 6, the step of dripping the fillermaterial 5 will be described. First, as shown in FIG. 5(a), the fillermaterial 5 is dripped onto the center part of each opening area 20 a byuse of a jet dispenser or an inkjet device. For this step, dedicatedmarks are provided along the perimeter of the production substrate, andthe positions to which the filling material 5 is to be dripped aredetected based on the marks. In this manner, the filler material 5 canbe dripped to desired positions. The opening areas 20 a shown in FIG. 5and FIG. 6 correspond to sub pixels included in a pixel. Assuming thatthe dripping amount of the filler material 5 is 8 pl in the case wherethe sub pixel pitch is 40 μm, the gap between the substrates 6 and 7that are bonded together can be about 5 μm.

As shown in FIGS. 5(b) and 5(c), the filler material 5 dripped to thecenter part of each opening area 20 a is pushed and expanded by pushingthe first substrate 7 and the second substrate 6 against each other.Since the dripped filler material 5 is supplied with a uniform pressurein this step, the filler material 5 can be pushed and expanded to anarea having an equal distance from the center part of each opening area20 a. As shown in FIGS. 6(a) and 6(b), when the filler material 5 ispushed and expanded, the adjacent dot portions of the filler material 5are fused together, and borders 55 along which the dot portions of thefiller material 5 are fused together are superimposed on thelight-blocking area.

In this state, as shown in FIG. 6(b), a bank layer 23 located at aborder line between the pixels or sub pixels prevents short circuitingbetween a pixel electrode and a common electrode included in the organicEL light-emitting layer 1. The bank layer 23 has a protruding shape andthus can be used to prevent the filler material 5 from expandingexcessively, so that the borders 55 along which the adjacent dotportions of the filler material 5 are fused together stay within an areasuperimposed on the light-blocking area.

As shown in FIG. 6(b), the common electrode and the sealing film 3provided on the bank layer 23 are raised to protrude by the thickness ofthe bank layer 23. As a result, a protrusion 24 is formed in the firstsubstrate 7, at a position corresponding to each of border lines betweenthe pixels. The protrusion 24 obstructs expansion of the filler material5 and thus the border 55 of the filler material 5 stays on theprotrusion 24. Use of the protrusion 24 makes it easy to control theborder 55 of the filler material 5 such that the border 5 stays withinan area corresponding to the light-blocking area including the blackmask 22.

As can be seen, in the step of dripping the filler material 5 in thisembodiment, the positions to which the filler material 5 is to bedripped are determined such that the borders 55 along which the dotportions of the filler material 5 are fused together will besuperimposed on the light-blocking area after the substrates areattached together, and then the filler material 5 is dripped. Owing tothis, even if the display irregularities 55 z are caused at the borders55 of the filler material 5, the display irregularities 55 z can be madedifficult to be visually recognized because the borders 55 are within anarea superimposed on the light-blocking area including the black mask22.

Example 1

Now, with reference to FIG. 7, a method for producing an organic ELdisplay device 10 in example 1 according to the present invention willbe described. FIGS. 7(a) through 7(c) are each a planar see-through viewof the organic EL display device 10, and show a process after the fillermaterial 5 is dripped to a center part of a pixel including four subpixels, namely, red (R), green (G), blue (B) and white (W) sub pixels.The same steps as those described above with reference to FIG. 4 throughFIG. 6 will not be repeated.

The filler material 5 may be dripped at a rate of one dot portion for aplurality of sub pixels. For example, as shown in FIG. 7(a), the fillermaterial 5 may be dripped to the center part of a lattice oflight-blocking area enclosing four opening areas 20 a that arerespectively located in correspondence with the four sub pixels R, G,Band W. In this case, a uniform pressure is applied to the fillermaterial 5 in the step of attaching the first substrate 7 and the secondsubstrate 6, and as shown in FIG. 7(b), the filler material 5 is pushedand expanded to an area having an equal distance from the center part.As a result, as shown in FIG. 7(c), the borders 55 along which adjacentdot portions of the filler material 5 are fused together are located inan area corresponding to the light-blocking area including the blackmask 22.

In this manner, like by the method for producing the organic EL displaydevice 10 in an embodiment according to the present invention describedabove with reference to FIG. 4 through FIG. 6, the borders 55 formed bythe fusion of the dot portions of the filler material 5 can becontrolled to be located in an area superimposed on the light-blockingarea including the black mask 22. Therefore, the organic EL displaydevice 10 produced by the method in example 1 according to the presentinvention does not allow the display irregularities 55 z, which may becaused by the borders 55 of the filler material 5, to be visuallyrecognized easily and has improved image quality.

Example 2

Now, with reference to FIG. 8, a method for producing an organic ELdisplay device 10 in example 2 according to the present invention willbe described. FIGS. 8(a) through 8(c) are each a planar see-through viewof the organic EL display device 10, and show a process after the fillermaterial 5 is dripped to a center part of a pixel including three subpixels, namely, red (R), green (G) and blue (B) sub pixels. The samesteps as those described above with reference to FIG. 4 through FIG. 6will not be repeated.

Even in the case where the sub pixels R, G and B are each of a lengthyrectangle as shown in FIG. 8(a), the filler material 5 may be dripped toa center part of each pixel including three sub pixels R, G and B. Inthis case, a uniform pressure is applied to the filler material 5 in thestep of attaching the first substrate 7 and the second substrate 6, andas shown in FIG. 8(b), the filler material 5 is pushed and expanded toan area having an equal distance from the center part. As a result, asshown in FIG. 8(c), the borders 55 generated by the fusion of the dotportions of the filler material 5 are located in an area correspondingto the light-blocking area including the black mask 22.

In this manner, like by the method for producing the organic EL displaydevice 10 in an embodiment according to the present invention describedabove with reference to FIG. 4 through FIG. 6, the borders 55 formed bythe fusion of the dot portions of the filler material 5 can becontrolled to be located in an area superimposed on the light-blockingarea including the black mask 22. Therefore, the organic EL displaydevice 10 produced by the method in example 2 according to the presentinvention does not allow the display irregularities 55 z, which may becaused by the borders 55 of the filler material 5, to be visuallyrecognized easily and has improved image quality.

As described above, according to the method for producing the organic ELdisplay device 10 in an embodiment according to the present invention,the dripping pitch of the filling material 5 can be decreased by use ofan existing jet dispenser or inkjet device, and therefore the displayirregularities 55 z that may be visually recognized can be alleviated.In addition, since the first substrate 7 and the second substrate 6 maybe formed with a narrow gap therebetween, color mixing in the pixels canbe prevented. Therefore, the resultant organic EL display device 10 canhave improved image quality, and can be produced by a simplified methodat lower production cost.

Also, according to the method for producing the organic EL displaydevice 10 in an embodiment according to the present invention, thefiller material 5 is dripped such that the borders 55 formed by thefusion of the dot portions of the filler material 5 will be located inan area corresponding to the light-blocking area. Therefore, the displayirregularities 55 z, even when being caused, can be prevented from beingvisually recognized. The present invention provides an organic ELdisplay device 10 that has improved image quality, realizes highdefinition display, and is produced at low cost; and a method forproducing such an organic EL display device 10.

What is claimed is:
 1. A method for producing an organic EL displaydevice, comprising: forming a plurality of pixels including an organicEL light-emitting layer on a substrate; forming an inorganic filmlocated above the organic EL light-emitting layer and covering theplurality of pixels; dripping an organic material at a plurality ofportions on the inorganic film by use of a jet dispenser or an inkjetdevice, the organic material being in contact with the inorganic film;and forming an organic layer by fusing the organic material, the organiclayer overlapping the plurality of pixels, wherein the plurality ofpixels has a plurality of sub pixels, a plurality of opening areas islocated in the plurality of sub pixels respectively, light from theorganic EL light-emitting layer is transmitted through each of theplurality of opening areas, a light-blocking layer demarcating theplurality of sub pixels is located above the organic layer, thelight-blocking layer has a first region and a second region, the firstregion surrounds one of the pixels, the second region is located insidethe first region and demarcates the opening areas included in the one ofthe pixels, the plurality of portions includes two portions adjacenteach other, the organic layer includes a border at which the organicmaterial of the two portions are fused together, and the border overlapsthe first region and does not overlap the second region in a planarview.
 2. The method for producing an organic EL display device accordingto claim 1, wherein the inorganic film is made of SiN.
 3. The method forproducing an organic EL display device according to claim 1, wherein theorganic material is made of a resin.
 4. The method for producing anorganic EL display device according to claim 3, wherein the organicmaterial is made of a thermosetting resin.
 5. The method for producingan organic EL display device according to claim 1, wherein the organicmaterial is dripped at a dripping pitch shorter than or equal to 100 μm.6. The method for producing an organic EL display device according toclaim 1, wherein the substrate includes a display area in which theplurality of pixels is arrayed, and the organic layer overlaps anentirety of the display area and an outside of the display areacontinuously in a planar view.
 7. The method for producing an organic ELdisplay device according to claim 1, wherein the one of the pixels hasfour sub pixels, the second region has a first part and a second part,the first part runs in a first direction, and the second part intersectsthe first part and runs in a second direction different form the firstdirection.
 8. The method for producing an organic EL display deviceaccording to claim 7, wherein the organic material is dripped at anintersecting portion where the first part and the second part intersecteach other.
 9. The method for producing an organic EL display deviceaccording to claim 1, wherein the one of the pixels has a plurality ofsub pixels arranged in a first direction, and the second region has aplurality of parts arranged in the first direction and running in asecond direction different from the first direction.
 10. The method forproducing an organic EL display device according to claim 1, wherein theone of the pixels has a first sub pixel, a second sub pixel, and a thirdsub pixel arranged in a first direction in this order, and the organicmaterial is dripped at an opening area of the second sub pixel.